Continuous ice cream freezer and dispenser



Jan. 30, 1962 P. CARPIGIANI CONTINUOUS ICE CREAM FREEZER AND DISPENSER Zz' I5 N/ 2i:

Filed March 31, 1959 OJ 7 a a 2/ 2 m a E w M w w n: w w 3 w u 5 I1 0N1: M M m :IJM a up x m a v INVENTOR PoERio CARPIG/AM ATTORNEY 8 United States 3,018,641 CONTINUOUS ICE CREAM FREEZER AND DISPENSER Poerio Carpigiani, 50 Viale Carducci, Bologna, Itaiy Filed Mar. 31, 1959, Ser. No. 8113,3113 Claims priority, application Italy Nov. 28, 1358 6 Claims. (Cl. 62-342) This invention relates to continuous ice cream freezers which may be employed both as bulk freezers and as package freezers and dispensers and aims to provide a freezer of this class. The invention is very simple in construction and reliable in use, which may be incorporated in a cabinet of good appearance and which permits of increasing the number of varieties of mixes requiring different proportions of air, which features have generally been employed up to date in said freezers.

Another object of the invention is to simplify the twopump systems as well as the single three-gear pump system used previously for incorporating air, and this is accomplished by the use of a very simple two-gear pump. This two gear pump is different from the prior freezers of the same class, by being incorporated in the cabinet, together with the suction and delivery pipes and with a vent valve, thus permitting a substantial pre cooling of the mix, without objectionable condensing of water vapor and frosting on parts outside the cabinet.

Another object of the invention is to provide an ice cream freezer in which all the outside metallic parts are not in contact with very cool fluids and the ice-dispensing end of the freezing asesmbly is nonmetallic.

Another object of the invention is to provide for mixing of the liquid mix in the feed tank during the operation of the machine, so as to permit of substantially cooling this mix without danger of involuntary freezing or formation of ice crystals.

Still another object of the invention is, in addition to a spring vent valve permitting the discharge of the emulsion of liquid mix and air from a vent opening in the delivery piping of the said gear pump, to provide a gear pump enclosed in a casing comprising a movable wall pressed by springs against other casing parts and the gears-of the pump and capable of being pushed by the same pumped mix out of contact with the said parts and gears whenever the pressure within the pump is excessive, so as to relieve said pressure by bypassing of the mix and its leakage through the slits formed in the casing.

Another object is to provide a freezer of the kind abovereferred to in which the delivery piping of the said gear pump is provided at its end with an easily dismountable ball or like valve and in which the said piping is made of easily mountable and dismountable sections.

The above and other objects and advantages of the invention will be apparent from the following specifications made with reference to the attached drawing, in which:

FIGURE 1 shows diagrammatically, in a longitudinal vertical section, the mixing chamber of a continuous ice cream freezer in which the mix feeder pump and annexed parts are enclosed in the freezer cabinet;

FIGURE 2 shows an embodiment of gear pump adapted to draw and deliver the mix into the system and metering in the air;

FIGURE 3 shows a longitudinal section in enlarged scale of a part of FIGURE 1, comprising the gear pump and a vent valve, the section being taken along the broken line III- III of FIGURE 2 and illustrates the possibility of driving the pump by a separate motor;

FIGURE 4 shows the simple means adapted for tightly connecting the dismountable tubular parts of the freezer.

With reference to the drawings, 1 denotes a substan- 3,9l8fi4l Patented Jan. 30, 1962 ies tially horizontal mixing and freezing cylinder of a continuous ice cream freezer and dispenser particularly adapted for directly dispensing ice cream in packages to the public.

Said cylinder 1, as well as the other parts of the freezing and mixing assembly now to be described, with the exception of the drive arrangement, are enclosed in a cabinet which comprise a rear part where said driving parts are mounted, and a front or dispensing part at the opposite side.

The said freezing cylinder is tightly closed and is cooled by a coil 2 fitted all around and embedded in a heat insulation material 3. Within the freezing cylinder 1 a co-axial mixer 4 having inclined paddles is fastened to a shaft 104 rotatably mounted through a hub-like part of the rear end of said cylinder 1, said part being provided with a packing 5. Shaft 4 carries a driving pulley 7 which is driven through a V-belt 6. The front end of said cylinder 1 is closed by a plate 8 preferably made of a non heat-conductive material, such as a plastic material or the like which also forms at least the casing 9 of the dispensing tap or faucet.

Within the cabinet C, above the mixing cylinder 1 the mix supply tank 10' is mounted. This tank is provided with a lid 11 and rests with a part of its bottom on a layer of substantially heat-conductive material 12 placed on the freezing coil 2 and surrounded by the heat insulation 3 of the freezing cylinder 1. By this arrangement, the liquid mix contained in the tank =10 is maintained at a low temperature, but well above the freezing point.

In the tank 10 a feed device is fitted which feeds a mix into the freezing cylinder 1 and into which a pre determined amount of air under pressure has been incorporated. This feed device comprises a gear pump 13 provided with only two gears, 14 and 15. The gear 14 sucks the liquid mix of tank 10 through an upright tube 16 provided with an adjustable valve 17, FIGS. 2 and 3. The gear 15 sucks air from the atmosphere, preferably through an adjustable valve 18 and incorporates same in the required proportions by adjusting valves 17 and 18, into the liquid mix, in alignment with the delivery 19 of said pump 13.

The gear pump 13 comprises a hollow casing section 211 provided with a projecting hub 21 which is co-axial to gear 15 and is inserted in a supporting bushing 22 of shaft 23 and tightly but rotatably fitted through said hub 21. On the outer end of shaft 23 the pump-driving pulley 25 is keyed, while on its inner, non-cylindrical end 123 the correspondingly shaped bore of the pump gear 15 is fastened. Pulley 2.5 is driven by the same mixer shaft (FIGURE 1) or by a separate motor M (FIGURE 3) driving pulley 7 by means of a belt drive 24. p

In the case as shown in FIGURE 1, the belt 24 is a V-belt driven by a V-pulley 26, which is preferably a self-tensioning pulley having a fixed half 126 and a slidable half 226 urged towards said fixed half by a spring .27 reacting against a head or flange 28.

The pump casing section 20 is closed by a cover 29 which constitutes the remaining pump casing section and carries the delivery nipple 19 and is urged against the edges of said casing 20 which is provided with a seal gasket 47, and against the gears therein by coil springs 31 threaded on the stems of screws 30 screwed through bores of said cover 29 into threaded bores of the casing 20, it being possible to adjust the force of said springs 31 by screwing more or less said screws 30.

Into the bore of nipple 19 one end of a pipe section 32 is inserted, the other end of which is inserted into the horizontal elbow end 233 of an upright aerated-mix delivery pipe 33 which ends in a flanged hu b 133 provided with a groove, in which an annular gasket 37 is inserted.

Said hub 133 has its flange adhering to the edges of a corresponding aperture of the tank and is tightly inserted in an upright extension 34 of the freezing cylinder 1. The outlet of said extension 133 is provided with a non-return valve or ball valve 45 held in proximity of said outlet by a dismountable pin 46. In order to permit of dismounting the pump 13 and pipe 33, the length of the connecting pipe section 32 is such as to come out of the elbow pipe end 233 when its opposite end is inserted to the bottom of the bore of nipple 19.

As it is apparent from the drawings, the above-described tubular parts or piping sections are simply inserted the one into the other, without screwing or other retaining means. The tightness of the joints is insured by annular gaskets 35, 36, 37, 3S and 39 inserted in part in corresponding retaining grooves. This permits of easy dismounting, and again mounting the various parts, for servicing or other purpose. Thus, this whole tank 10 including the pump and other parts may be dismounted as a whole by simply disconnecting the belt 24 and taking the part 133 out of the extension 34.

Pipe section 32 is further provided with a vent valve 41 which is pressed against its seat by coil spring 42 reacting against the perforated cover 43 which is screwed on the walls of a bell-shaped chamber containing said valve. Said pipe section also carries a pressure gauge 44 which indicates the pressure existing in said pipe section, the maximum pressure being adjustable by adjusting the force of spring 42 by screwing more or less said cover 43.

The operation may be summarized as follows: The operating conditions of the pump and the incorporation of air are first adjusted by regulating the liquid mix inlet valve 17 and the air inlet valve 18.

The normal Working pressure of the pump is adjusted by regulating the pressure of springs 31 and the maximum pressure within the delivery pipe section 32 is set by adjusting the pressure of the spring 42, by screwing more or less the cover 43. The said adjustments are such that, by normal operation, any pressure in excess of the normal working pressure promotes the lifting of some millimeter or fraction of millimeter of the pump cover 29, thus creating a bypass between inlet and outlet inside of the pump and at the same time, by detaching the said cover from the adjoining gasket 47, permits a leakage of liquid mix, which thus runs back into the tank 10. When, however, in the freezing cylinder 1, the desired filling has been reached, or when due to exceptional circumstances the lifting of the pump cover 29 is not sufficient to keep the pressure of the aerated mix in the tube section 32 Within the desired limits, the vent valve 42 is opened and the fluid flows from within said pipe section 32 into the bellshaped casing 40 and through the holes in the cover 43 flows down into the tank 10.

It may be noted that the ball valve 45 at the outlet end 133 of the aerated mix delivery pipe 33 serves mainly for preventing the pressure in freezing cylinder 1 from falling below the working limits when the pump is stopped and the tap 9 is closed.

While the ice cream freezer thus described has been shown for convenience and simplicity of drawing as comprising a single freezing assembly, it is apparent that, without departing from the spirit of the invention and without changing something in the machine construction, it will be possible to arrange two and even three or more cylinders with annexed parts in a single cabinet, this arrangement being usually required whenever ice cream having different flavors should be dispensed.

I claim:

1. A continuous ice cream freezer and dispenser comprising a cabinet, at least one mixing and freezing cylinder in said cabinet, a freezing coil surrounding said cylinder, heat insulating material surrounding said freezing cylinder and said coil, a shaft rotatably mounted in said cylinder having inclined paddles for forcing the contents of the cylinder towards one wall of said cabinet,

selectively operable outlet means on said one wall for selective communication with the cylinder for dispensing the contents thereof, a liquid mix supply tank in said cabinet at least partially overlying the freezing coil, a gear pump having at least two gears disposed within said supply tank and including a liquid intake operatively associated with one of said gears and an air intake communicating with the atmosphere and operatively associated with the other of said gears, valves for controlling said intakes, a tubular extension connected to said liquid intake having one end thereof disposed at the lower end of the supply tank, said gear pump having a delivery port at a position where the gears intermesh so that the liquid mix and the air to be incorporated therein are forced toward said port, a delivery conduit in communication with said delivery port and that end of said cylinder opposite its connection to the outlet means, a springbiased vent valve in said delivery conduit opening into the liquid mix supply tank to discharge thereinto the liquid mix and air when excessive pressure is present, said gear pump including a hollow pump casing section defining said intakes and leaving one side of the gears exposed, and a cover plate provided with a delivery port constituting the remaining casing section, means for mounting said cover plate so as to tightly but resiliently close said hollow casing section by adhering against the exposed side of said gears, whereby said cover permits of lifting same under the action of a sufficiently high pressure of the fluid being pumped by said pump and permitting bypassing and leakage of said fluid back into said tank.

' 2. A continuous ice cream freezer and dispenser comprising a cabinet, at least one mixing and freezing cylinder in said cabinet, a freezing coil surrounding said cylinder, heat insulating material surrounding said freezing cylinder and said coil, a shaft rotatably mounted in said cylinder having inclined paddles for forcing the contents of the cylinder towards one Wall of said cabinet, selectively operable outlet means on said one wall for selective communication with the cylinder for dispensing the contents thereof, a liquid mix supply tank in said cabinet at least partially overlying the freezing coil, a gear pump having at least two gears disposed within said supply tank and including a liquid intake operatively associated with one of said gears and an air intake communicating with the atmosphere and operatively associated with the other of said gears, valves for controlling said intakes, a tubular extension connected to said liquid intake having one end thereof disposed at the lower end of the supply tank, said gear pump having a delivery port at a position where the gears intermesh so that the liquid mix and the air to be incorporated therein are forced toward said port, a delivery conduit in communication with said delivery port and that end of said cylinder opposite its connection to the outlet means, a spring-biased vent valve in said delivery conduit opening into the liquid mix supply tank to discharge thereinto the liquid mix and air when excessive pressures is present, said gear pump is a two-gear pump; a hollow casing section having one side open and enclosing all of said two gears but one side thereof; said liquid intake port being defined in said casing section opening in correspondence of the teeth of one of the gears in a position spaced from the meshing point of said gears; said air intake port in said casing section, opening in correspondence of the other of said two gears, in a position spaced from the meshing point of said gears; a cover plate for said casing section, resilient means for mounting said cover plate so as to tightly close said open side of the casing and adhere against the said exposed gear side and the edges of said casing section; said delivery port being defined in said cover plate, provided in correspondence of the teeth of both said gears, in proximity of their meshing point; means for slidably but tightly mounting in said delivery port the end of said delivery conduit; said mounting of the said pump cover plate and delivery conduit being such as to permit a slight movement of said pump cover plate away from the said hollow casing section and gears, thus creating a bypass and a leakage gap between said hollow casing section and cover.

3. A continuous ice cream freezer and dispenser comprising a cabinet, at least one mixing and freezing cylinder in said cabinet, a freezing coil surrounding said cylinder, heat insulating material surrounding said freezing cylinder and said coil, a shaft rotatably mounted in said cylinder having inclined paddles for forcing the contents of the cylinder towards one wall of said cabinet, selectively operable outlet means on said one wall for selective communication with the cylinder for dispensing the contents thereof, a liquid mix supply tank in said cabinet at least partially overlying the freezing coil, a gear pump having at least two gears disposed within said supply tank and including a liquid intake operatively associated with one of said gears and an air intake communicating with the atmosphere and operatively associated with the other of said gears, valves for controlling said intakes, a tubular extension connected to said liquid intake having one end thereof disposed at the lower end of the supply tank, said gear pump having a delivery port at a position Where the gears intermesh so that the liquid mix and the air to be incorporated therein are forced toward said port, a delivery conduit in communication with said delivery port and that end of said cylinder opposite its connection to the outlet means, a spring-biased vent valve in said delivery conduit opening into the liquid mix supply tank to discharge thereinto the liquid mix and air when excessive pressure is present, said gear pump having a substantially deep bore provided with an annular gasket inserted in a groove thereof; said delivery conduit including a horizontal pipe section inserted in said bore and provided with a pressure gauge and a vent valve; an upright descending tube provided with an elbow part inserted on the free end of said horizontal pipe section with an annular gasket therebetween, said upright tube being inserted through the walls of the said tank and of the said cylinder into a part projecting upwardly from the rear end of said cylinder, and means for effecting a tight seal between the descending tube and the said walls and part of said tank and cylinder, the whole being so arranged as to permit of dismounting by a simple pull the pipe sections and of lift-ing and dismounting from the freezing machine the assembly of supply tank and pump.

4. A continuous ice cream freezer and dispenser comprising a cabinet, at least one mixing and freezing cylinder in said cabinet, a freezing coil surrounding said cylinder, heat insulating material surrounding said freezing cylinder and said coil, a shaft rotatably mounted in said cylinder having inclined paddles for forcing the contents of the cylinder towards one wall of said cabinet, selectively operable outlet means on said one wall for selective communication with the cylinder for dispensing the contents thereof, a liquid mix supply tank in said cabinet at least partially overlying the freezing coil, a gear pump having at least two gears disposed within said supply tank and including a liquid intake operatively associated with one of said gears and an air intake communicating with the atmosphere and operatively associated with the other of said gears, valves for controlling said intakes, a tubular extension connected to said liquid intake having one end thereof disposed at the lower end of the supply tank, said gear pump having a delivery port at a position where the gears intermesh so that the liquid mix and the air to be incorporated therein are forced toward said port, a delivery conduit in communication with said delivery port and that end of said cylinder opposite its connection to the outlet means, a spring-biased vent valve in said delivery conduit opening into the liquid mix supply tank to discharge thereinto the liquid mix and air when excessive pressure is present, a heat conductive material disposed between and directly contacting said freezing coil and said supply tank, whereby said tank is cooled somewhat by said freezing coil.

5. In an ice cream freezer, a cabinet, at least one freezing cylinder in said cabinet, a freezing coil surrounding said cylinder, means in said cylinder for forcing the contents of the cylinder towards one wall thereof, outlet means on said one Wall for communication with the cylinder, a liquid supply tank in said cabinet, pump means including a liquid intake in communication with said supply tank and an air intake in communication with the atmosphere, means for controlling said intakes, delivery means in communication with said pump and another wall of said cylinder opposite said one wall, said pump means being disposed in said supply tank, and a heat conductive layer disposed between said supply tank and the freezing coil, whereby the liquid from the supply tank to the cylinder is precooled.

6. In an ice cream freezer, a cabinet, at least one freezing cylinder in said cabinet, a freezing coil surrounding said cylinder, means in said cylinder for forcing the contents of the cylinder towards one wall thereof, outlet means on said one wall for communication with the cylinder, a liquid supply tank in said cabinet, pump means disposed within said supply tank and including a liquid intake in communication with said supply tank and an air intake in communication with the atmosphere, means for controlling said intakes, delivery means in communication with said pump and another wall of said cylinder Opposite said one Wall, and said pump means including a casing having one wall thereof resiliently biased to a closed position and movable to an open position with respect to the casing when excessive pressure is present to permit liquid in said casing to be discharged between the casing and said one wall and directly into said supply tank.

References Cited in the file of this patent UNITED STATES PATENTS 1,779,330 PfoutS Oct. 21, 1930 1,902,346 Vogt Mar. 21, 1933 1,951,412 Hill Mar. 20, 1934 2,211,387 Routh Aug. 13, 1940 2,219,656 Miller Oct. 29, 1940 2,765,745 Sadler Oct. 9, 1956 2,777,393 Woodruif Jan. 15, 1957 2,896,421 Rader July 28, 1959 

